Telephone-exchange system



C. L. eoona'u'm'. TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED SEPLH, I916.

Patented Mar. 23, 1920.

2 SHEETS-SHEET ,l.

/n venfor: Char/e5 L. Good/um 'A My 2 SHEETSSHEET 2.

Patented Mar. 28, 1920.

Charles L. Goad/um. y

c. L. 6000mm,- TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED SEPT-11,1916- WWW-WWW mww UNITED STATES PATENT onnron.

CHARLES Il- GOODRUM, OF BROOKLYN, NEW YORK, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y.,' A CORIE'ORATION OF NEW YORK.

Specification of Letters Patent.

Patented Mar. 23, 1920.

' Application filed September 11,1916. Serial No. 119,506.

To all whom it may concern:

' Be it known that I, CHARLEsLANE Goon. RUM, a citizen of the United States, res1ding at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Telephone- Exchange Systems, of which the following is aRfull, clear, concise, and exact description.

\This invention relates to a class of service indicating arrangement, which may be ap- -plied to automatic or semi-automatic systems. Y v

The mainjfeature of this invention resides in associating characteristic tone generators with the test circuits of the subscribers lines, so that these tones are inductively connected to the operatofls position upon the extension of a calling line to that position.

The other features of the invention will be specifically pointed out in the following detailed description and claims.

Referring to the drawings, Figures 1 and .2, with Fig. 1 placed at the left of Fig, 2, diagrammatically represent a telephone system embodying the present invention. The portion of the diagram at the left of the dotted line in Fig. 1 represents all the apparatus individual to one subscribers line and a portion of thevapparatus individual to another subscribers line in the same group; the portion of the diagram included between the dotted lines of Figs. 1 and 2 represents a line finder and its associated circuits; that portion of the drawings at the right of the dotted line in Fig. 2 shows a first selector and an operators telephone set with its connecting plug and jack.

The invention hereirr disclosed is devised to transmit a characteristic signal or tone from the calling line to the operators position. By this arrangement, the operator is informed of the class of service to which the calling subscriber is entitled.

The invention will be best understood by a detailed description .of the o erations in-j volved in interconnecting a su station, with the operators position.

When the subscriber at substation 110 removes his receiver, a circuit is closed for the line relay 116, said circuitleading over the line circuit conduc tors 111and112', and through the telephone set of substation 110. This relay thereupon closes a circuit. for. re-

lay c to start a' finder searching for this calling line, This. circuit leads from-the free pole of battery, through the left-hand winding of relay 116, left-hand armature and back contact of the cut-off relay 120, conductor 121, contacts 117, 118-, conductor (5, left-hand armature and back contact of. relay a, conductor 13 1, relay 0 to ground. Relay 0 thereupon locks itself up in series with the line relay 116 in a circuit leading through its left-hand armature and front contact, said circuit being independent of relay 0;. Relay 0, at its right-hand armature and front contact, closes a circuit for the escapement magnet 217, to move the steering switch of the line finder into position 2,. to begin the upward movement of .the brush rod to cause the set OfrWlPBlS of this line group to test for the calling line, as-

suming that the line findernormally associated with the starter wire 130 is not in use. Undersuch assumption, an arm 214 of the finder brush rod is in contact with a metallic segment 265, individual to this line group. This circuit is as follows: free pole of battery, magnet 205 (Fig. 2), conductor p, 212, magnet 217, conductor 218, arm 216,

conductor 215, arm 214, segment 265, conductors 130,127, right-hand armature and front contact of relay 0 to ground. The magnet 205 is so adjusted and the circuit conditions are such, that it does not operate when this circuit is closed. The magnet 217, upon its energization, moves the steering switch. toposition 2, in which position the circuit for the said magnet 217 is maintained closed. This circuit may be traced as follows: free pole of battery, magnet205, conductor 212, magnet 217, conductor 218, arn'n 216, now in its second position, conductor 287,- conductors 202, 201, arm 200, conductor 129, right-hand armature and front, contact of relay EQconductors 128, 127, right-hand armature and front contact of relay '0 to ground. The relayb was energized upon the energization of relay 0. This relay is madeslowacting for a purpose set forth later.

The arm 210 of the steering switch in its second position closes a circuit for magnet 207, which, by interrupting its own circuit, raises the brush rod,durmg which movement the set of brushes wipes over the group containing the calling line. This circuit is as follows: free pole of the battery, sec .ondary magnet 207, conductor 219, arm

210 audits second: contact, conductors 209,

208, armature and back contact of magnet 207, conductors 268, 266, right armature and front contact of magnet 217, conductor 267, conductor 204, armature and back contact of release magnet 203, conductors 202, 201, arm 200, conductor 129, right-hand armature and front contact of relay 5, con- 'ductors 128, 127, right-hand armature and .front contact of relay 0' to ground. When the brushes 221, 222 and 223 arrive upon the terminals 224, 225 and 226, representing the line of the subscriber initiating the call, the cut-off relay 120 of such line is energized over the following circuit: free pole of the battery, relay 120, conductor 114, terminal 226, brush 223, conductor 113, contacts 228, 270 of magnet 217, conductor 271, resistance 272, conductor 201, arm 200, conductor 129, right-hand armature and front contact of relay 7), conductors 128, 127, right-hand armature and contact of relay 0 to ground. Cut-off relay 120, at its left-hand armature, opens the circuit of relay 0, which in deenergizing, opens the circuit of driving magnet 207, The finder is thus brought to rest upon the calling line terminals and is held there by holding means, not shown. WVhen the cut-ofl? relay 120 operates-and deenergizes the relay a, the escapement magnet 217 also is deenen gized, whereupon the steering switch moves to its third position. The closure of contacts 228, 229 of magnet 217 puts ground on the multiple test terminals of this line, whereby connection cannot be made to it by a connector.

- In the third position, the arms and 233 of the steering switch connect the line conductors 111, 112 through to the line relay 234 of a selector. It will, of course, be understood that the operations involved in connecting the calling line with a connecting circuit just traced. take but a short interval of time. The line relay 234, at its .armature and frontcontact, closes a circuit for a slow-acting relay 235. The subscriber will now operate his sender. The relay 234 is'adjusted to respond to each interruption of the line circuit, but the relay 235 is arranged to remain energized during such interruptions. Each time the armature of the relay 234 closes its back contact, an impulse is given to a rotary'driving magnet 236 to cause the brush rod of the first selector to be rotated, to position the roper set of brushes below a group of trun rs terminating in operators" positions serving the desired group of subscribers. This circuit is as follows: free pole of battery, magnet 236, conductor 269, contact 237, which is closed as lon as the brush rod is in its normal longitudinal position, conductors 233.

239, armature and front contact or slowacting relay 235, armature and back contact of relay 234 to ground. At the end of this series of impulses, a relatively long interruption of the line circuit occurs, which causes the slow-acting relays 235 and 240 to become deenergized. It will be noted that relay 240 was energized upon the first deenergization of relay 234- by a circuit leading through the armature and front, contact of slow relay 235. The relay 240, at its front contact, closed a circuit for the escapement magnet 241 of the steering switch of the selector, which, however, did not permit the steering switch to move. lVh'en the relay 240 is denergized, it opens the circuit of escapement magnet 241. This permits the steering switch to move to its second osition to cause the set of brushes 246, 244, 248, which has thus been positioned, to hunt over the group of trunks for an idle trunk.

As soon as the steering switch arrives in its second position, a circuit is closed for the vertical drivingmagnet 242 of the selector. This circult may be traced'as follows: free pole of battery, magnet 242 and its armature and back contact, steering switch arm 243 and its second contact, conductor 244, conductor 245, armature and front contact of relay 234 to ground. The magnet 242 thereupon makes and breaks its own circuit, thus causing the brushes 246, 247 and 248 to wipe over the fixed contacts 249, 250 and 251. An idle trunk is represented by ground on the test contact 251 thereof. Therefore, when the test brush 24S reaches the contact 251 of an idle trunk, a circuit is closed from the free pole of battery, escapement magnet 241, arm 252 and its second contact, conductors 253, 254, brush 248, test contact 251, conductor 255. contact 275, back contact and armature of relay 271 to ground.

The escapement magnet is thereupon energized and moves the side switch to its third position. Relay 271 is then energized over a circuit which may be traced from grounded battery, relay 271, jack contact 296, trunk conductor contact 250, brush 247. wiper 257 in its third position, lower side of the line, wiper 233 in its third position, brush 225, conductor 112, telephone apparatus 110, over .the upper side of the line.

through conductor 111, brush 221-, wiper ill ll to the operators position, characteristic tone generators herein indicated at 136 and137. These tone generators indicate to the operator the class of service to which the calling subscriber is entitled. The characten istic tone generator associated with substation 110 is inductively connected to the operators position over the following circuit: from grounded battery, secondary winding of the induction coil 135, cut-ofi' relay 120, conductor 11 1, contact 226, brush 223, conductor 113, contacts 228 and 229, conductor 230, left-hand armature and hack contact of relay 203, and primary winding of the induction coil 291 to ground. 'lhe interrupter at 136, by means ot the primary winding of the coil, induces an alternating current in the circuit just de scribed.- The primary winding of coil 291 induces an alternating current in the secondary winding of this coil, which is in a circuit which may be traced from grounded battery, secondary winding out coil 291, release magnet 2o1.oitnorn1al contact 260, conductor 259, wiper 258 in its third position, conductor 25%, brush 248, contact 251, com ductor 255, sleeve 294: of the jack, sleeve 293 ot the plug, conductor 290, listening key 27 6, a winding of the induction coil of the operators head set, condenser 298, to ground.

At the termination of the conversation, the operator removes the plug from the jack, which completes a circuit for restoring the switches to their normal position. This circuit may be traced from tree pole of battery, release magnet 261 ot' the selector, 0H"- nornial contact 260, conductor 259, wiper 258 in its third position, conductor 254-, hrush 24-8, contact 251, conductor 255, contact 275, armature and back contact or relay 271 to ground. A1 circuit in parallel with the last named circuit serves to release the tinder switch. This circuit leads from tree pole othattery, release magnet208, finder oil-normal contact 262, conductor 269, righthand armature and hack contact oi relay a, conductor 264e, conductor 281, conductor 259, wiper 259 and its third contact, conductor 25 t, .hrush 24in, contact 251, conductor 255, contact 275, armature and hack contact ot relay 271, to ground.

The numerals 131 and 132 designate respectively the line relay and cut-off relay of another suhscrihens line terminating at the finder switch. The tone generator 13? associated with this line is of diiierent irequcncy troni the tone generator shown in 19 5, by which the operator is alole to dis tinguish between the various calling lines to which she may be connected.

llt should be noted in connection with this system that the characteristic tone is inductively connected to the operator s position over a circuit in addition to, and independent ot, the talking conductors connect ing any substation of the group served, with the operators position.

Obviously, the invention is not limited to the specific embodiment herein shown and described, but is capable of many variations and applications without departing from its spirit and scope.

that is claimed is:

1. In a telephone system, an operators position, incoming line circuits, a trunk circuit leading to said position, means for interconnecting any incoming line circuit with said trunk circuit, a characteristic tone generator associated with said incoming line circuits,-and a circuit independent of the talking conductors of said trunk circuit and incoming line circuits for inductively connecting said generator to said operators position.

2. In a telephone system, an operators position, incoming line circuits, a trunk circuit for interconnecting said operators position with any incomincr circuit, characteristic tone generators associated with said incoming line circuits, and another circuit lllthd pendent of the talking conductorsof said trunk circuit for inductivelyconnecting one of said generators to said operators position.

3. In a telephone system, an operators position, incoming line circuits, a trunlr circuit, means for associating said position with one'end, and means for associating any in coming line circuit with the other end of said trunk circuit, a test circuit associated with said last mentioned means, character istic tone generators associated with said incoming circuits, and another circuit independent or the talking conductor of said trnnlr circuit but including a portion of said test circuit tor inductively connecting said generators to an operators position.

t. la a telephone system, an operators position, incoming line circuits, a trunk circuit leading to said operatofis position, means for interconnecting any incoming line with said trunlr circuit, release mechanism tor said interconnecting means, a release circuit for controlling said mechanism, a characteristic tone generator associated with said incoming line circuits, and a circuit independent ot the tallting conductor at said trunk circuit hut'including a portion oil said release circuit tor inductively connecting said generator to the operators position.

.5. in a telephone system, an operators position, incoming line circuits and a trunlr circuit having talking conductors leading to said operators positionla switch tor in tcrconnia'l'ing any with said trunk circuit, operating means for said switch. a test circuit associated with said switch. release means for said operating means, a release circuit for controlling said release means, a character incoming line circuit istic tone generator associated with said incoming line circuits, and a circuit independent of the talking conductors of said trunk circuit but including portions of said test ing said generator to said operators po-' by said release mechanism, a characteristic tone generator associated with some of said incoming lines, and a circuit independent of the. talkin conductors of said trunk circuit but including a portion of said test circuit for inductively connecting said generator to said operators position.

7. In a telephone system, an operators position, incoming line circuits and a trunk circuit leading to said position, a switch for interconnecting any incoming line circuit with said trunk circuit, means for operating said switch, an escapement magnet for controlling said operating means, release mechanism I for restoring said switch to normal position, operating circuits for controlling said escapement and release Inagnets, a test circuit associated with said switch andcontrolled at one point by said escape magnet and at another by said release mechanism, a characteristic ton'e enerator associated with said incoming lines,

and a circuit including a portion of said test circuit "for inductively connecting said tone generator to the operators position.

- -8.. In'a telephone system, an operators position, incoming line circuits, means ineluding two automatic switches for extend- -1n any vof said incoming line circuits to said operators position, -a test circuit at one of said switches and a release circuit-at the other switch arranged to be inductively connected together, a characteristic tone generator associated with certain of said incoming line circuits, and-a circuit including portions of said test circuit and said release cirsaid tone generator to said operators position.

9., In a telephone system, incomingline circuits, an operators position, means including two automatic switches for interconnecting any incoming line circuit to said operatorsposition, a test circuit associated with each of said switches, a tonegenerator associated with certain of said incoming line circuit and means including portions of said test conductors for connecting said generator to said operators position.

10. In a telephone system, incoming line circuits, an operators position, means 111- cluding twoautomatic switches for interconnecting any incoming line circuit to said operators position, a ,test circuit associated with each of said switches, a tone generator associated with certain of said incoming line circuits, and means includin portions of said test conductors ,for inductively connecting said generator to said operators po sition.

11. In a telephone system, incoming line circuits, an operators positi'on,-trunk lines terminating in jacks at said position, means including automatic switches for extending any incoming line circuit to any trunk line,

atone generator associated with certain of said incoming lines, means independent of the talking conductors of said trunk lines for connecting said tone generator to any of said jacks-and means cooperating wit said jacks for detecting tones.

12. In a telephone system, incoming line circuits, an operators position, trunk lines terminating in jacks at said position, means including automatic switchesfor extending any incoming line circuit to any trunk line, a tone generator associated with certain of said incoming lines, means independent of the talking conductors of said trunk lines for inductively connecting said tone generator to any of said jacks, and means cooperating with said jacks for detecting tones.

13. In a telephone system, incoming line circuits, an operators position, trunk lines terminating in jacks at said operators position, an operators telephone set connectible to any ack, means for interconnecting any incoming line with any trunk line, a tone generator associated with certain of said incoming lines, and means independent of the talking conductors of said trunk for inductively connecting said. generator to said operators telephone set.

14. In a telephone system, incominglinc circuits, an operators position, trunk lines terminating in jacks at said operators position, an operators telephone set connect ible to any jack, means for interconnecting any incoming line with any trunk line, a tone generator associated with certain of said incoming lines, and means independent of the talking conductors of said trunks for inductively connecting said nerator to the sleeve conductor of said jac s.

In witness whereof, I hereunto subscribe my name this f8thflday of September A. D., 1916.

' CHARLES L. GOODRUM. 

